This invention relates to a vending machine in which a plurality of separate slave vendor units are connected addibly or detachably to a master vendor.
Since the number of article conveying columns in a vending machine is physically fixed, an extra vending machine must be additionally provided if the kind of articles to be handled by the vending machine is to be increased. Each vending machine, however, has a coin mechanism, a vend possible judgment device, an article selection device and an article conveying device and, if the article conveying device is to be increased, the coin mechanisms, vend possible judgement devices and control devices related thereto are necessarily provided by the number of the vending machine increased notwithstanding the fact that the article selection devices and the article conveying devices only need to be increased. Such superfluous provision of the coin mechanism etc. results in waste of the manufacturing cost and therefore is quite uneconomical.
For overcoming such defect, there has recently been proposed what may be called a master-and-subunit vending machine. According to this proposal, a master vendor having independent functions of a vending machine is provided and one or more subunit vendors having only the article selection and conveying functions and having no coin mechanism are connected to the master vendor. An example of such master-and-subunit vending machine is disclosed in Japanese Patent Publication No. 57-27511. Judging from the construction of the article conveying control circuit of the proposed vending machine, the article conveying control circuit to be included in a single vending machine is simply divided into several control circuits corresponding to several article selection switches and each of the divided control circuits is disposed in each subunit vendor as the article conveying control circuit for the subunit vendor and these subunit vendors are connected to the master vendor by electrical wiring. While an article conveying operation is performed in one subunit vendor, connection between all other subunit vendors and the master vendor is cut off and the respective subunit vendors are incapable of operating independently from one another.
It is, therefore, an object of the invention to provide a vending machine comprising a master vendor having at least a coin mechanism and vend possible judgement means and one or more separate slave vendors having no coin mechanism combined to the master vendor characterized in that the respective slave vendors are capable of operating as independently from one another as possible.
In view of the fact that the prior art vending machine in which plural vendor units are connected to a master vendor necessitates a large number of wiring for connection, it is another object of the invention to simplify the connection wiring by improving an information transmission and receiving system between the master vendor and the slave vendors.